Field of the Invention
The present invention relates to an information processing apparatus, a method of controlling the same, and a storage medium.
Description of the Related Art
In an information processing apparatus connectable to a LAN network (Local Area Network), such as a printer, scanner, facsimile apparatus, or multi-functional peripheral, the communication rate is increasing as the amount of data to be processed increases. A maximum communication rate set in a PHY (Physical Layer) as a physical layer of a LAN interface is represented by a physically transmittable maximum bit rate per unit time such as 1,000, 100, and 10 Mbps. As the maximum communication rate of an apparatus including a LAN interface thus increases, the power consumption of the PHY also increases. Since demands for energy saving are increasing in recent years, demands have arisen for a high communication rate and low power consumption of a network.
To realize power saving of an information processing apparatus, apparatuses having an electricity saving function which partially stops internal power supply or temporarily stops functions when neither access nor an operation has been performed for a predetermined time are spreading. It is also possible to decrease the communication rate of the PHY to a minimum rate at the timing at which this electricity saving state begins, and perform linking again, thereby reducing the power of the PHY while using a network. In this case, however, the communication rate of the PHY is changed, so the link is disconnected, and packet dropping may occur during the disconnection.
As a method of realizing power saving without disconnecting a link while maintaining the highest communication rate of the PHY, there is a method which uses a PHY having an EEE (Energy Efficient Ethernet) function. The EEE is a standard formulated by IEEE802.3az, and is a technique which realizes power reduction of a network while establishing a link of the PHY when there is no network traffic for a predetermined time. This EEE includes a method of realizing power reduction by stopping some functions of the PHY and a MAC as an upper layer of the PHY in accordance with a network traffic. This method is called an LPI (Low Power Idle).
Japanese Patent Laid-Open No. 2013-027991 has proposed a method of enhancing the electricity saving effect of an information processing apparatus by using the LPI. This method stops, when the EEE is enabled, an image processing clock in an apparatus in addition to a communication clock, if conditions for shifting to the LPI are satisfied, or if no image formation data has been received from a network for a predetermined time.
Unfortunately, Japanese Patent Laid-Open No. 2013-027991 does not take account of the EEE function and a method of setting of the communication rate of the PHY when the above-mentioned power saving function is enabled.